Quote from: OROBTC on February 22, 2017, 09:52:15 PM

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Bitmixer.io for one has addresses that expire in 24 hours. They then DELETE the address & account info. As far as I know, that means any BTC arriving late is GONE. And that would be terrible for the unwary who might lose a big chunk of money when the blockchain is stopped-up...

With my original message I just wanted to clarify that bitcoin addresses don't expire the way you think. Services set their own time limit for payment requests but addresses don't expire.

Quote from: BITMIXER.IO on June 30, 2016, 09:51:04 AM

Please ALWAYS save (and verify) Letter of Guarantee before send us coins! If something goes wrong, we can't help you without a Letter of Guarantee. The support team doesn't have access to mixing transactions, the database is encrypted, moreover we delete all order's info after 24 hours. We keep the private key of the generated address for several days, so if you sent coins after 24 hour we still can process your order ONLY if you have the Letter of Guarantee.

As you can see in this message quoted from official BITMIXER account, they keep private keys for some days after that 24h deadline. Maybe they wait for 7 days, 14 days, 1 month or whatever... we don't know

In conclusion, the unique expiration that exists here is the time they decide they'll offer a service for you. Anyway, I think that this is completely third-party service offtopic and my intention was just to clarify the expiration concept.